Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the description correctly focuses on value beyond them: concrete returned fields plus risk warnings (1-of-n, modules), and unusually explicit rate-limit and payment mechanics (10 free calls/day, $0.002/call via x402 params._meta or X-API-Key). It stops short of saying whether a non-Safe address yields an error or a false flag, which is the main behavioral unknown.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three compact segments: the core question, the field inventory, then commercial terms. Front-loaded and no sentence is filler; the pricing clause is operationally necessary rather than padding.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Output schema exists, so return-value documentation is optional, and annotations already cover safety semantics; the description still adds field-level expectation and cost. The gap is the non-Safe-address behavior and any version/module-support caveats across the listed chains, which an agent would want before calling.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and both parameters (chain, address) already carry descriptions and examples including the allowed chain list, so the description adds nothing parameter-level. Baseline 3 applies when the schema does all the work.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Opens with a direct question that names the resource ('Is this address a Safe multisig?') and then enumerates the exact payload: owners, threshold (m-of-n), nonce, version, modules, guard, fallback handler, risk warnings. That enumeration clearly separates it from generic siblings like contract_read or address_profile without needing to name them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The framing 'Is this address a Safe multisig?' implies the when-to-use case (validating/auditing a Safe), and the mention of risk warnings hints at a security-review scenario. However, it never states when NOT to use it, what it returns for a non-Safe address, or which sibling to prefer for generic contract/address inspection.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.